A183998 Number of (n+1) X 5 0..2 arrays with all 2 X 2 subblock sums the same.

855, 1233, 1887, 3309, 6111, 12525, 26655, 61125, 144495, 361293, 925647, 2471829, 6713631, 18762045, 52968255, 152326725, 440454735, 1288454253, 3779340207, 11166335349, 33034529151, 98175588765, 291944589855, 870672034725

Offset

1,1

Comments

Column 4 of A184003.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 6*a(n-1) - 60*a(n-3) + 85*a(n-4) + 150*a(n-5) - 360*a(n-6) + 396*a(n-8) - 216*a(n-9).

Empirical g.f.: 3*x*(285 - 1299*x - 1837*x^2 + 14429*x^3 - 4146*x^4 - 47992*x^5 + 37500*x^6 + 49140*x^7 - 48600*x^8) / ((1 - x)*(1 - 2*x)*(1 - 3*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Apr 09 2018

Example

Some solutions for 3 X 5:
..2..0..1..0..2....2..1..2..1..0....2..0..1..1..2....1..1..1..2..1
..1..2..2..2..1....0..1..0..1..2....0..2..1..1..0....0..1..0..0..0
..1..1..0..1..1....2..1..2..1..0....1..1..0..2..1....2..0..2..1..2

Crossrefs

Cf. A184003.

Sequence in context: A185639 A105275 A100969 * A209502 A198527 A234885

Adjacent sequences: A183995 A183996 A183997 * A183999 A184000 A184001

Keyword

nonn

Author

R. H. Hardin, Jan 08 2011

Status

approved